Detection of bioelectric potential by a hybrid assistive limb during acute stage rehabilitation

Abstract

We report a case of successful detection of bioelectric potential from the paretic leg muscles during acute stage of rehabilitation using a Hybrid Assistive Limb (HAL). A 56-year-old woman suffered a left severe hemiparesis after the clipping surgery of a ruptured aneurysm. Bed side rehabilitation was conducted from postoperative day 2 and rehabilitation using HAL from postoperative day 7. Initially no voluntary movement was observed in the left paretic leg muscle while minimal bioelectric potential was detected from the rectus femoris muscle, vastus lateralis muscle, and biceps femoris muscle when she was standing with the assistance of HAL. On postoperative day 9, bioelectric potential was detected from all monitored muscles during voluntary extension of the non-affected leg. Voluntary movement of the affected leg was then observed together with an increase in selective and phasic bioelectric potential. On postoperative day 22, the patient was able to walk without using HAL. Contralateral leg movement may facilitate selective and phasic muscle activities during acute stage rehabilitation after a stroke. HAL could assist the paretic leg by preventing falls and could provide feedback to patients relating to their walking posture, facilitating acute phase rehabilitation.